Japanese Patent Publication No. 2000-159048 discloses an automotive air bag apparatus which is provided to prevent an passenger's head etc. from contacting with a sidewall of vehicle cabin at the vehicle collision while absorbing its impact energy. This air bag apparatus is installed on the vehicle's interior side of a roof-side rail so as to extend along the fore-and-aft direction of the vehicle. The apparatus is also adapted so as to inflate its air bag body from an interior side of an automotive roof-side rail downwardly at the vehicle side collision.
The air bag body includes a plurality of chambers separated from each other in the fore-and-aft direction of the vehicle, a duct part in common with the chambers and a plurality of gas induction ports for communicating the duct part with the chambers. Under an inactivated condition of the air bag apparatus, the air bag body is folded and accommodated between the side face (interior side) of the roof-side rail and a roof trim for covering the roof-side rail and a roof panel.